htlcswitch: report incoming htlc time lock with FinalIncorrectCltvExpiry

Previously the time lock in the onion payload was reported. This is no
new information to the sender.

htlcswitch/link.go

@@ -2856,9 +2856,7 @@ func (l *channelLink) processExitHop(pd *lnwallet.PaymentDescriptor,
 			"time-lock: expected %v, got %v",
 			pd.RHash[:], pd.Timeout, fwdInfo.OutgoingCTLV)
 
-		failure := lnwire.NewFinalIncorrectCltvExpiry(
-			fwdInfo.OutgoingCTLV,
-		)
+		failure := lnwire.NewFinalIncorrectCltvExpiry(pd.Timeout)
 		l.sendHTLCError(pd.HtlcIndex, failure, obfuscator, pd.SourceRef)
 
 		return true, nil